The following article discusses the idea when short term rates are lower than 'natural' interest rates, then gold prices tend to rise.

If treasury bill rates are meant to fall below zero due to the Taylor Rule, then gold prices should be well supported. Just another perspective on negative real rates, but this time with the emphasis on short term rates, rather than ten-year bond rates.

http://advisoranalyst.com/glablog/2014/07/25/a-deep-dive-into-a-model-that-helps-explain-gold-prices.html

-F6